Abstract:

According to the different bases of Actin gene sequences between Phytophthora capsici Leonian，P. infestans and other eight common soil pathogenic pathogens，we designed and screened out a specific primer pair YM2F/YM2R to establish a real-time fluorescent quantitative PCR detection assay of P. capsici，and using this assay to monitor P. capsici in soil samples prepared by artificial simulation and collecting form attacked yields. The results showed that the assay had a good liner relationship and a high sensitivity of 1 × 10-1 pg ? μL-1 DNA，which is 100 times more than normal PCR. P. capsici could be detected rapidly，specifically and quantitatively in infected soil without isolation or cultivation by the RT-PCR assay. The detection result of soil samples collected form attacked field indicated that the incidence and epidemiology of disease were proportional to the density of pathogenic bacteria within a certain range，which can provide scientific basis for the epidemic and early prevention of the disease.

Key words: Phytophthora capsici, pumpkin, real-time fluorescent quantitative PCR, detection assay, Actin